The purpose of the Clinical Core is to provide biological specimens and behavioral data to Projects 1-3. The Core is hosted by the Division of Adolescent and Young Adult Medicine that has a 38 year history of conducting research in adolescents and young adults. The Division has extensive experience in the recruitment and retention of at risk and HIV infected adolescents and young adults, and adults in clinical trials, with a case load of approximately 3,000 HIV-youths and 150 HIV+ youths (30 of who are in transition to adult care) ages 12-24 in care and over 300 adults in research. The Core is located at the Adolescent and Young Adult Medicine Clinic, a clinical and research center for adolescents and young adults In Baltimore City. The Clinic has recently doubled its space to expand research activities related to RTIs, HIV, and health disparities clinical trials. The P.I. has been independently funded since 1992 to conduct studies in diverse populations and has been the recipient of federally funded collaborative research studies for the last 16 years. The Core research personnel are well trained in human subject protection, HIPAA, Good Clinical Practice, and handling of biohazard specimens. The team has expertise in the recruitment, retention and protection of human subjects, in particular minors. Core research personnel will be responsible for collecting all required biological samples such as genitourinary swabs, endocervical swabs, blood, and behavioral data through the Audio Computerized Assisted Interview (ACASI). Our clinicians will perform the reproductive health examinations, and provide diagnosis and management. In addition, the clinical counseling personnel will provide primary and secondary prevention through our prevention and health education team. Research personnel will include the Core Director, Study Coordinator, Research Outreach Specialist and Clinician. Additional research and administrative personnel will offer support. The team will conduct weekly research team meetings to assure completion of project 1, 2 and 3 activities. These meetings will have the participation of principal investigators, laboratory staff, clinical and bidnformatics cores. Human subject protection and research appropriateness will be monitored by the IRB, our Division Research Task Force and the Youth Community Advisory Board. Our site characteristics and long history of successful research implementation make us uniquely qualified to conduct projects 1, 2 and 3.